Hand dryer



NOV. 11, 1958 1 w CARLSN `2,859,535

HAND DRYER Filed slept. 15. 1953 JNVENTOR.- lIHN W. CARLSON United This invention relates in general to a drying apparatus particularly adapted for use in the drying of the hands and face and is of the general character which has particular usefulness in commercial establishments such as industrial plants, hotels, restaurants, and the like.

Heretofore, hand dryers located in the washrooms of such industrial or other commercial establishments have been electrically operated wherein a motor drives a fan which creates air pressure and wherein the air thus caused to circulate passes over heating elements and then outwardly through an outlet opening. Such devices have proven in practice to be relatively expensive to manu facture as well as expensive to operate and to maintain in repair. Furthermore, such devices have not been eflicient in their drying operations because of the wide outlet area which directs the exhaust of the warm air in a diverging stream thus losing a considerable amount of the effectiveness thereof.

One of the principal objects therefore of the present invention is to provide a drying apparatus of the character above referred to which is designed to overcome many of the disadvantages inherent in those similar devices presently in use.

Another object of the invention is to provide a drying yapparatus which is more ecient and utilizes more of the warm exhaust air for drying purposes than has been possible in the similar devices in use at the present time.

A further object of the invention is to provide a drying apparatus adapted for use in commercial establishments wherein compressed air rather than an electric motor is used to create the warm air stream.

A still further object of the invention is to provide a drying apparatus wherein a novel form of timing device is utilized for regulating and determining the amount of time during which the apparatus may be operated.

Still another and more specific object of the invention is to provide an outlet covering for the outlet of a drying apparatus wherein the eiciency of the apparatus in its drying operation is considerably increased.

Other objects and advantages of the invention will become apparent upon reading the .following description taken in conjunction with the accompanying drawing, in which- Fig. l is a front elevational view of a drying apparatus embodying the present invention, and

Fig. 2 is an enlarged vertical transverse sectional view through the apparatus of Fig. l and taken along the plane of line 2%-2 of Fig. l.

In general, the apparatus `consists of an external housing 1 having an outlet opening 2 at the front side thereof and in which opening there is disposed a concave dished plate 3. The plate 3 is provided with a plurality of elongated slots 4 spaced apart over its area in any suitable arrangement but preferably one which is similar to that shown in Fig. l.

The effect of this concave plate 3 and the arrangement of the openings therein will be brought out more fully hereinafter. It is sutlcient for present purposes to state ...tes Patent O 2,859,535 Patented Nov. 11, 1958 ice that this general design of plate which covers the area of the outlet opening in the apparatus has the effect of creating converging air streams rather than diverging, thus resulting in greater efficiency.

Referring now more particularly to Fig, 2, there is illustrated the operating mechanism within the housing 1. The shaft 5 is mounted within the housing to extend transversely thereof, which shaft has mounted thereon a ratchet wheel 6 and a cam 7. There is also mounted on the shaft 5 an impeller wheel 8 which has radially extending outwardly therefrom a plurality of spaced impeller blades 9.

A torsion spring 10 also surrounds the shaft 5 and is connected at one end thereof to the impeller Wheel 8 and at its other end to the ratchet `wheel 6. There is thus a yieldable connection between the impeller 8 and ratchet wheel 6 allowing a certain amount of relative movement between these two members but causing the ratchet wheel to be rotated by the impeller 8 when the torsion spring is taut.

The cam 7 must be fixed to rotate with the ratchet Wheel 6 in which Case they may be keyed directly together, or both the ratchet wheel 6 and cam 7 may be keyed to the shaft 5 in which case the impeller 8 will rotate freely upon the shaft.

The ratchet wheel 6 forms a part of the escapement mechanism which also includes the escapement device 11 mounted for swinging movement on a shaft or pin 12. The member 11 is provided with spaced apart legs 13 and 14 each of which terminate in the inwardly extending detent lingers 15 and 16. Also associated with the escapement mechanism is a suitable device for causing the member 11 to swing back and forth in the manner of a pendulum and in the embodiment of the invention shown herein a pendulum 17 is shown as associated therewith, whereby the member 11 4will swing from side to side and alternately engage the detent fingers 15 and 16 with the teeth on the ratchet wheel 6.

An air inlet tube 18 extends upwardly through the bottom of the housing and is adapted to be connected with a source of compressed air. This creates no problem in most instances because of the customary presence of compressed air lines in most of the industrial and com.- mercial establishments where the apparatus is designed to be used.

The air inlet tube 18 is provided with a narrowed por: tion 19 to provide a valve seat 20 against which a valve member 21 is adapted to seat. The valve member 21 is provided with a stem 22 `which passes through a guide member 23 and upon which guide member a Vcoiled cornpression spring 24 is adapted to rest at one end. The other end of spring 24 bears upwardly against the valve member 21, thereby to maintain the valve in a normally closed position.

The air inlet tube 18 then extends upwardly and is provided with a relatively large opening provided by cutting the tube angularly as shown at 25. This opening faces toward the impeller wheel 8 and is in close proximity to the blades 9 thereon so that air under pressure passing outwardly of the tube 18 will have suicient force against the impeller blades to rotate the impeller and operate the escapement mechanism.

The cam 7 is provided with a cut-out portion in the periphery thereof thereby to provide a shoulder 26 against which one arm 27 of a bell crank lever 28 may abut. When the arm 27 is in place as shown in Fig. 2 it will prevent rotation in a counter-clockwise direction of the cam 7 and consequently will also prevent rotation of the ratchet wheel 6 and impeller 8. When the arm 27 is moved out of the path of the shoulder 26 on the cam 27 then the cam, ratchet wheel and impeller are all free to rotate.

Y The bell crank 28 is pivotally mounted on a pin 29 and has the other arm 30 thereof extending downwardly and outwardly as at 31 and is provided at its outer end with a suitable k-nob or handle 32. The portion 31 pro-V jects through a suitable opening 33 in the front part .of the housing 1. It will thus far be evident that inward pressure on the knob 32 will cause a rotation of the bell crank 28 about the pivot pin 29 and will disengage the arm 27 from the shoulder '26 on the cam.

A third arm 34 is also mounted on the pivot pin 29 and is secured to the arm 39* of the bell crank by means of the pin and slot connection 35 and 36. The end of arm 34 extends below and in contact with a second bell crank 37 having a forwardly extending arm 38 and a rearwardly extending arm 39. This bell crank is mounted to rotate about the pivot pin 40. The inner end of arm 39 extends through an opening 4l in the side of the vinlet tube 18 and in contact with the upper end of a stem 42 extending upwardly from the valve member 21. It will, therefore, be clear from the construction thus far described that inward pressure on the knob 32 will also cause the arm 34 to move upwardly whereupon rotation of the bell crank 37 in a clockwise direction will move the arm 39 thereof downwardly to depress the stem .42 and open the valve 21 against the force of spring`24.

Thus, it will be seen that inward pressure on theknob will not only open the valve 21 to permit entrance of the compressed air but will also release the cam 7 for rotational movement. The compressed air entering against the impeller blades 9 will rotate the impeller in a counterclockwise direction and will carry with it the ratchet wheel 6 and cam 7. As soon as pressure on the knob 32 is released, the arm 27 will ride upon the edge of cam 7 until one complete revolution thereof has been made at which time the arm 27 will immediately drop into place below the shoulder 26 and stop further rotation thereof. When this movement of the bell crank occurs, the arm 34 thereon will also drop downwardly and permit the spring 24 to close valve 21 and return the rbell crank 37 back to its normal position shown in Fig. 2.

The escapement mechanism prevents the cam from rotating too fast and will provide a definite time period required for the cam and its associated parts to complete a single revolution. Thus, as soon as the arm 27 releases the .cam 7 for movement, the incoming compressed air will begin rotation of the impeller which is connected to the ratchet wheel 6 by means of the torsion spring 10. The pendulum 17 then operates to swing the member 11 back and forth and cause the'rotational parts to rotate in a step by step movement. It is contemplated that with the mechanism disclosed herein and the proportions illustrated it will require approximately thirty seconds for the various parts to make one complete revolution.

The purpose of the torsion spring connection between the impeller and the ratchet wheel is to insure a completion of the cycle in the event that the how of ,air is cut olf for any reason. That is to say, if a person begins to use the device and it has run for ten or fteen seconds and the air ow is suddenly stopped, there is no further force to continue rotation of the impeller wheel. With the torsion spring connection as above described, the impeller wheel may stop its rotation but the force of the spring will cause the ratchet to continue to rotate for a sufficient length of time to bring the cam 7 back into its normal inoperative position. When the next user of the apparatus .depresses the Vknob 32 yand the force of the air stream causes. the impeller 3 to rotate, it will immediately take up any slack as between the ratchet wheel and the impeller and thereafter will continue to operate as long as the impeller wheel rotates to carry the ratchet wheel and cam therewith.

Anarrn 43 pivoted intermediate its ends at 44 is p0- sitioned so that one end 45 thereof is normally against 4 tube 1S.

4 l one of the impeller blades 9 to prevent rotation of the impeller in a clockwise direction. This might possibly occur by force of the spring i@ when the air supply is cut ofI before the end of the cycle. The arm 43 thus prevents movement of the impeller in the opposite direction and insures completion of the cycle as a result of the spring connection withlthe ratchet wheel. A spring 46 secured at one end to the lever 43 and at its other end to a pin 47 maintains the end 45 thereof in contact withthe blades on the impeller.

A plurality of heating elements generally indicated at 43 is positioned in the upper part of the housing and above the separating partition 49 which confines the incoming air to a relatively Vsmall area. The heating elements 43 are suitably mounted upon an insulation plate 5@ which may have in association therewith a shield 51 surrounding in part the inlet end of the compressed air Wires 52 and 53 are'connected 'to a suitable source of electricity and through a switch member 54. The switch 54 is Vof the customary type and has a switch arm 55 associated Vtherewith adapted to close the circuit to the heating Velements when depressed. The arm 30 of the bell crank 28 is provided with a projection 56 adapted to contact switch arm V55 and depress the zsame when the knob 32 is moved inwardly. It will thusbe seen that the apparatus'is caused to begin its cycle upon depressing the knob 32 which will not only release the cam 7 and its associated escapement mechanism and impeller for rotation, but will also open valve 21 to permit the entrance of compressed air and will close the circuit to the heating elements 4S.

The timing mechanism is thereby operated by means of the incoming compressed air and this air after driving the impeller passes upwardly and over the heating elements 48 to be heated. The concave plate 3 which is positioned over the outlet opening will have a retarding effect on the air and enable it to become heated before passing outwardly. Furthermore, the use of the slots 4 and their arrangement substantially as shown gives the effect of jets of warm air passing outwardly therethrough, all of which jets are directed toward each other so that none of the warm air is lost to the atmosphere without first having contacted the hands or face of the user. Heated air itself has certain drying qualities and air pressure Aalso has such qualities. The force of the air is maintained or even increased by the use of the outlet slots 4 and since this air has also been heated by the heating elements 48 there results a combination of the warm air under pressure thereby increasing the drying efficiency thereof.

The concave shape of the cover plate 3 also enables the user to place his hands or face within the contines thereof and thereby to obtain immediately the effect of the jets of warm air passing outwardly therethrough.

From the foregoing it will be evident that the apparatus embodying the present invention is more economical to manufacture than those embodying the use of electric motors and is more efficient in the manner in which the air is directed toward the object to be dried. ln many of the larger models currently in use it is necessary to provide stands so that they may rest upon the oor. In the present instance the apparatus is suhciently simple and light in weight so that it may be mounted for example upon the wall 57 of a room and may have an insulation plate 5S interposed between the housing of the apparatus and the wall.

Changes may be made in the form, construction and arrangement of parts from those disclosed herein without in any way departing from the spirit of the' invention or sacrificing any of theattendant advantages thereof, orovided, however, that such changes fall within the scope of the claims appended hereto.

The invention is hereby claimed as follows:

1. A drying apparatus of the class described compris- 'ing, a housing, air inlet means adapted to admit air under pressure into said housing, valve means normally closing said air inlet means, manually operable means for opening said valve to permit the ow of air through said inlet means, heating means within said housing for heating the air flowing through said inlet means, outlet means for the heated air, and timing means Within said housing operable by the air flowing through said inlet means for closing said valve and stopping the how of air after a predetermined period of time.

2. A drying apparatus of the class described comprising, a housing, air inlet means adapted to be opened to admit air under pressure into said housing, means normally closing said inlet means, heating means Within said housing for heating s aid air under pressure, outlet means for the heated air, normally inoperative timing means for permitting air l'lovv through said air inlet means and for controlling the energization of said heating means for a predetermined time period, said timing means operable by the air llo'vving through said inlet means and manually operable means for opening said air inlet means, energizing said heating means and releasing said timing means.

3. A drying apparatus of the class described comprising, a housing, an air inlet adapted to be opened to admit air under pressure into said housing, means normally closing said inlet, normally inoperative heating means within said housing for heating air iiowing through said air inlet, outlet means for the heated air, normally inoperative timing means for timing the period of air ow through said inlet and for controlling the energization of said heating means, said timing means being pneumatically actuated by said air ow, and manually operable means for opening said air inlet, for rendering said heating means operative, and for releasing said timing means for operation.

4. A drying apparatus of the class described comprising, a housing, an air inlet adapted to be opened to admit air under pressure into said housing, means normally closing said inlet, normally inoperative heating means Within said housing for heating air flowing through said air inlet, outlet means for the heated air, normally inoperative timing means for timing the period of air flow through said inlet and for controlling the energization of said heating means, said timing means being pneumatically actuated by said air flow, and manually operable lever means for simultaneously opening said air inlet, for rendering said heating means operative, and for releasing said timing means for operation.

5. A drying apparatus of the class described comprising, a housing, an air inlet adapted to admit air under pressure into said housing, valve means normally closing said inlet, a timing mechanism in said housing operable by the flow of air through said inlet, locking means to maintain said timing mechanism inoperative, manually operable means adapted to be actuated to open said valve and release said locking means, thereby to permit ow of air into said housing and operate said timing mechanism, heating means Within said housing to heat the air from said inlet, and air outlet means in said housing for the air thus heated.

6. A drying apparatus of the class described comprising, a housing, an air inlet adapted to admit air under pressure into said housing, valve means normally closing said inlet, a timing mechanism including an escapement device in said housing operable by the ilow of air through said inlet, locking means to maintain said timing mechanism inoperative, manually operable means adapted to be actuated to open said valve and release said locking means, thereby to permit iiow of air into said housing and operate said escapement device, means associated with said escapement device to return said locking means to locking position and to close said valve after a predetermined period of time, means in said housing to heat the air from said inlet, and air outlet means in said housing for the air thus heated.

7. A drying apparatus of the class described comprising, a housing, an air inlet adapted to admit air under pressure into said housing, valve means normally closing said inlet, a timing mechanism in said housing operable by the iiow of air through said inlet, locking means to maintain said timing mechanism inoperative, manually operable lever means adapted to be actuated to open said vaive and release said locking means, thereby to permit ow of air into said housing and operate said timing mechanism, heating means within said housing to heat the air from said inlet, and air outlet means in said housing for the air thus heated.

8. A drying apparatus of the class described comprising, a housing, an air inlet adapted to admit air under pressure into said housing, valve means normally closing said inlet, a timing mechanism in said housing operable by the ilow of air through said inlet, locking means to maintain said timing mechanism inoperative, manually operable means adapted to be actuated to open said valve and release said locking means, thereby to permit flow of air into said housing and operate said timing mechanism, heating means within said housing to heat the air from said inlet, air outlet means in said housing for the air thus heated, and cam means associated with said timing mechanism to engage said locking means and close said valve after a predetermined period of time.

9. A drying apparatus of the class described comprising, a housing, an air inlet adapted to admit air under pressure into said housing, valve means normally closing said inlet, a timing mechanism including an escapement device in said housing operable by the flow of air through said inlet, locking means to maintain said timing mechanism inoperative, manually operable lever means adapted to be actuated to open said valve and release said locking means, thereby to permit ow of air into said housing and operate said escapement device, means associated with said escapement device to return said locking means to locking position and to close said valve after a predetermined period ot time, means in said housing to heat the air from said inlet, and air outlet means in said housing for the air thus heated.

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